Steel-concrete combination backbone beam with big cantilever corrugated steel web overhanging beam

Abstract

The invention discloses a steel-concrete compounding spine girder that carries large cantilever waveform steel paunch board raising girder. It includes steel box girder, steel raising girder, and concrete bridge panel. The steel raising girder is set on the two sides paunch board of steel box girder along the portrait direction, the roof of the steel raising girder is on the same plat of that of steel box girder. And the steel raising girder adopts waveform steel paunch board. The concrete bridge surface is set on the roof of steel box girder and the steel raising girder. The invention could improve the landscape orientation prestressing force efficiency of the bridge panel, and decrease the avulsion loading and can simplify the processing.

Description

technical field [0001] The invention mainly relates to the field of bridge structures, in particular to a steel-concrete composite backbone beam with a large cantilever corrugated steel web cantilever used in bridge structure design. Background technique [0002] In the early 1970s, a prestressed concrete spine structure appeared abroad, that is, a single spine with a large cantilever slab structure. The earliest example was the viaduct next to the San Francisco Airport designed by T.Y.Lin; domestic Shanghai City in the 1990s In the early 1990s, a viaduct with a prestressed concrete ridge continuous beam structure was built on the inner ring road, with a span of 30m. The cross-sectional layout of the prestressed concrete ridge beam structure is shown in Figure 1, which is mainly composed of a concrete main beam 10, a concrete cantilever 11 and a concrete bridge deck 12. Concrete cantilever beams 11 must be spliced ​​with concrete main girders 10 during the construction of c...

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Problems solved by technology

This steel-concrete composite spine beam structure has the following disadvantages: 1. The steel cantilever beam 21 is lowered to the position below the neutral axis of the steel box girder 20 in this composite beam structure, which will reduce the driving clearance under the bridge, and the steel box The top surface of the beam 20 is higher than the traffic lane and also reduces the traffic width of the bridge deck, so this composite beam structure is generally suitable for the main beam structure of long-span cable-stayed bridges, but not suitable for urban bridges with medium and small spans; 2 .The planar steel web is used in the cantilever cantilever beam of the composite beam structure. Due to its high axial rigidity, it produces a large lateral constraint on the bridge deck concrete, which will cause serious loss of lateral prestressing force of the cantilever structure and reduce the efficiency of lateral prestressing. , so it is not advisable to apply transverse prestress in the concrete bridge deck of this structure, as a result, the concrete slab at the root of the cantilever will be prone to cracking, and a large tearing load will be generated on the web of the steel box girder

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